Identification of carbon-encapsulated iron nanoparticles as active species in non-precious metal oxygen reduction catalysts
| Autor: | Andrew A. Gewirth, Richard T. Haasch, Janis Timoshenko, Tim T. Fister, Jason A. Varnell, Anatoly I. Frenkel, Charles E. Schulz, Edmund C. M. Tse |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
inorganic chemicals
Hydrogen Catalyst support Science Inorganic chemistry General Physics and Astronomy chemistry.chemical_element Nanoparticle 02 engineering and technology 010402 general chemistry 01 natural sciences Article General Biochemistry Genetics and Molecular Biology Catalysis Metal Chlorine heterocyclic compounds Multidisciplinary organic chemicals General Chemistry 021001 nanoscience & nanotechnology 0104 chemical sciences chemistry visual_art visual_art.visual_art_medium 0210 nano-technology Platinum Carbon |
| Zdroj: | Nature Communications, Vol 7, Iss 1, Pp 1-9 (2016) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | The widespread use of fuel cells is currently limited by the lack of efficient and cost-effective catalysts for the oxygen reduction reaction. Iron-based non-precious metal catalysts exhibit promising activity and stability, as an alternative to state-of-the-art platinum catalysts. However, the identity of the active species in non-precious metal catalysts remains elusive, impeding the development of new catalysts. Here we demonstrate the reversible deactivation and reactivation of an iron-based non-precious metal oxygen reduction catalyst achieved using high-temperature gas-phase chlorine and hydrogen treatments. In addition, we observe a decrease in catalyst heterogeneity following treatment with chlorine and hydrogen, using Mössbauer and X-ray absorption spectroscopy. Our study reveals that protected sites adjacent to iron nanoparticles are responsible for the observed activity and stability of the catalyst. These findings may allow for the design and synthesis of enhanced non-precious metal oxygen reduction catalysts with a higher density of active sites. Determining active species in non-precious metal catalysts for the oxygen reduction reaction remains a challenge due to catalyst heterogeneity. Here the authors perform gas-phase treatments on an iron-based catalyst to allow the identification of carbon-encapsulated iron nanoparticles as the active species. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|